1) Field
The general inventive concept relates to a surface acoustic wave (“SAW”) element, a SAW device and methods for manufacturing the same.
2) Description of the Related Art
A SAW sensor is, in general, a device that detects a target material in a sample using a piezoelectric material. An oscillation signal is applied to the SAW sensor. Using an interdigital transducer (“IDT”) electrode included in the SAW sensor, the oscillation signal is converted into a SAW, which is a mechanical wave, and vice versa.
When the target material in the sample is bound to the surface of the SAW sensor, a surface mass of the SAW sensor may change due to the material bound to the surface. The target material being bound to the surface of the SAW sensor may cause a change in a SAW which is generated by the IDT electrode.
Further, when the target material is a biological material, the sample may include salt. A leakage current may undesirably flow through the sample having the salt from the portions of the SAW where electrical signals are input to the SAW sensor or output from the SAW sensor. When the leakage current occurs, a wave for oscillation or resonance is not be generated in the SAW sensor, resulting in the SAW sensor not being able to accurately sense the target material.